Automobile head lamp



Oct. 30, 1928. 1,689,378

B. A. BROUGHTON AUTOMOB ILE HEAD LAMP Filed Jan. 18, 1926 Patented Oct. 30, 1928.

' UNITED STATES PATENT OFFICE.

BERLIN ARTHUR BROUGHTON, OF CLEVELAND HEIGHTS, OHIO, ASSIGNOR TO DELTA ENGINEERING LABORATORIES, INC., OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

AUTOMOBILE HEAD LAMP. 1

Application filed January 18, 1926.

This invention relates generally to automobile headlights and more particularly to the manner of mounting the incandescent lamp in the reflector.

At the present time incandescent lamps having two independently lighted filaments are coming into use, each filament being of substantially the same candle power so that equal illumination will be obtained from either filament.

In the manufacture of these double filament lamps the filaments are placed substantially equidistant above and below the axis of the lamp. If the lamp constructedin this manner is placed within a reflector having a substantially central socket, onefilament will be arranged above the axis of the reflector and the other one below the same end with a parabolic reflector this arrangement would pro duce a quantity of divergent rays of light which would require considerable correction by means of prismatic lenses arranged in advance of the source of light.

The object of my invent-ion is to provide an arrangement whereby when the lamp is inserted in the centrally disposed socket one filament will be located on the axis of the reflector and the other one above said axis. Vith this arrangement there will be the minimum of divergent rays to be corrected by means of the headlight lens.

Another object of the invention is to So construct the parts that no particular care is necessary in inserting the lamp as it will always be given the proper tilt or inclination in order to bring the lower filament on the axis of the reflector. The invention also consists in certain details of construction hereinafter fully described and set forth in the appended claims.

In the drawings forming a part of this specification, Fig. l is a view showing the practical application of my invention the parabolic reflector being shown 1n section; Fig. 2 is a top plan view of the socket and the lamp arranged therein; Fig. 3 is a detail sectional view on the line 33 of Fig. 1; and Fig. 4 is a view showing the upward tilt of the lamp when used in connection with my improved construction of socket.

In carrying out my invention I employ the usual parabolic reflector 10 having a ce'u trally disposed lamp socket 11. This lamp Serial No. si 873.

socket is of the usual type except that it is mounted so that the bayonet slots 12 and 13 at the forward end thereof will be arranged one above the other and furthermore it will be noted that the transverse end of the upper slot 12 is arranged farther to the rear than the transverse end of the lower slot 13, as most clearly shown in Fig. 2; the upper slot being .lshown in full lines and the lower one in dotted ines.

The lamp 14 has two filaments 15 and 16, said filaments being arranged equidistant above and below the axis 17 of the lamp, as shown in Fig. 4. The lamp also has the usual transverse pins 18 for engagement with the bayonet slots of the socket and the filaments are so arranged with reference to the transverse pins that it is immaterial how the bulb is fitted into the socket. It will be given a slight upward tilt, due to the fact that the upper slot 12 is arranged rearward of the lower slot 13 and the forward end of the socket is slightly yielding to permit this upward movement. This slight upward tilt is suflicient to bring the lower filament 15 on the axis of the reflector placing, the upper filament above said axis.

Inasmuch as the bayonet slots are at the top and bottom of the forward end of the socket, it is obvious that there can be sutficient expansion of the forward end of the socket to permit the upward tilting of the lamp due to the fact that the upper slot has its transverse end arranged further to the rear than the transverse end of the lower slot.

With a. parabolic reflector and the centrally disposed lamp socket, this arrangement of two filaments is the most advantageous inasmuch as there will be the minimum number of reflected rays of light projected above the horizontal to be taken care of by a lens in advance of the source of light. The lower filament is the main or driving light and when passing other vehicles or for city driving the upper filament is cut in and the lower one extinguished.

It will thus be seen that I provide a simple and efficient arrangement for accomplishing the various objects hereinbefore recited.

Having thus described my invention, what I claim is 2 1. The combination with a reflector, of a fixed centrally d1 spose l socket havi bayonet of, the rear end of the upper slots being to the rear of the rear end of the lower slot, and a bulb having two filaments, said filaments being spaced equidistant above and below the axis of the bulb that when said bulb is inserted in the forward end of the lamp socket one of said filaments will be positioned on the axis of the reflector and the other one above said axis.

In testimony whereof, I hereunto aflix my sio'nature.

BERLIN ARTHUR BROUGHTON. 

